This invention relates to a carrier hinge assembly suitable for suspending adjacent panels, such as those of folding doors, from a track. In particular, the invention is directed to a carrier hinge assembly having a positive locking mechanism for preventing excessive rotation of the hinge pin.
A carrier hinge assembly is used to suspend a pair of hinged panels (such as the panels of a folding door) from an overhead horizontal track while permitting the panels to pivot relative to each other about a vertical hinge axis. An example of a carrier hinge is illustrated in Australian patent no. 726943 and the disclosure of that patent is incorporated herein by reference.
The known carrier hinge assembly has a wheeled carriage which rides along the track. A vertical hinge pin is attached to the carriage and depends therefrom. A hinge is formed on the vertical hinge pin, and comprises a pair of leaves, each hinge leaf being attached, in use, to the edge face of a respective panel.
Throughout the specification, including the claims, where the context permits, the term xe2x80x9cpanelxe2x80x9d is intended to include the generally planar closure components of folding doors, windows, shutters, screens and similar closures. The invention will be described with particular reference to its application to panels of a folding door system, but without limitation thereto.
A carrier is sometimes referred to in the trade as a xe2x80x9changerxe2x80x9d and the use of the term xe2x80x9ccarrierxe2x80x9d or xe2x80x9ccarriagexe2x80x9d in the specification is intended to include a hanger or like device.
An advantageous feature of the carrier hinge assembly of Australian patent no. 726943 is that it permits height adjustment of the suspended panels. Such adjustment may be required from time to time to prevent the door panels from sticking, or otherwise to facilitate smooth movement of the door panels. For this purpose, the upper portion of the hinge pin is threaded into the carriage, so that the vertical position of the suspended door panels relative to the carriage or track can be adjusted by rotating the hinge pin. The lower end of the hinge pin is typically formed as an enlarged head with a screwdriver slot, to allow the hinge pin to be turned with a screwdriver.
It is important to ensure that once the hinge assembly has been properly adjusted, it does not lose its adjustment i.e. that there is no undue rotation of the hinge pin. Australian patent no. 726943 teaches the use of a locking nut to lock the hinge pin against undesired rotation. The locking nut is screwed against the carriage so that the hinge pin is effectively clamped to the carriage and held frictionally against relative rotation.
A disadvantage of the known locking nut arrangement is that the locking nut is often difficult to access, as it is typically positioned very close to the track in use. (The nut may be concealed by a pelmet). Further, locked nuts inevitably become loose over time, allowing the hinge pin to turn and eventually causing the door panels to become misaligned. It is widely recognised in the industry that adjustment mechanisms for folding doors are very difficult to secure, and users are resigned to folding doors coming out of adjustment over time.
It is an object of this invention to overcome the above described disadvantage by providing a carrier hinge assembly having a locking mechanism which guards against loss of adjustment by preventing excessive rotation of the hinge pin.
It is another object of the invention to provide a carrier hinge assembly having a locking means which is more readily accessible and easier to operate than conventional locking nuts.
In one broad form, the invention provides a carrier hinge assembly for suspending adjacent panels from a track, the assembly including:
a carriage adapted to travel along the track;
a hinge comprising a hinge pin depending from the carriage, the hinge pin being rotatable about its longitudinal axis relative to the carriage, and at least one hinge leaf pivotable about the hinge pin, the hinge leaf being adapted to be fixed to an edge face of a respective panel, in use; and
a locking mechanism for keying the hinge pin to the hinge leaf to prevent relative rotation there between.
The hinge pin is typically threaded into the carriage. In this manner, the distance between the hinge leaf and the carriage (and hence the height of the panels) can be varied by rotating the hinge pin about its axis. The carriage may be provided with a depending boss having a threaded bore therein which receives a threaded upper end of the hinge pin.
In one embodiment, the locking mechanism comprises a lock member, in the form of a lock tongue or key, which is adapted to locate simultaneously in the hinge pin and the hinge leaf so that it prevents relative rotation between the hinge pin and the hinge leaf. In this embodiment, the hinge pin has a first axial slot in its lower end, and the hinge leaf has a second axial slot in its lower end. The first and second slots can be axially aligned by relative rotation of the hinge leaf and the hinge pin. When the slots are axially aligned, the lock member can locate in both slots, to thereby key the hinge pin to the hinge leaf.
Typically, the hinge pin has an enlarged head at its lower end which forms an axial stop for the hinge leaf. The first slot is provided in the enlarged head. The second slot is typically provided in a knuckle portion of the hinge leaf.
The lock member is preferably biased into engagement with the second slot by a biasing device, such as a spring. The lock member is retractable against the bias of the spring to enable it to withdraw from the second slot, and thereby permit relative rotation between the hinge pin and the hinge leaf.
The lock member may suitably be a planar key member which locates in the first slot, and can slide axially into engagement with the second slot. The key member may have an angled outer end overlying the lower end of the hinge pin, to enable it to be grasped and retracted against the bias of the spring. A removable spacer may be used to hold the key member in a retracted position against the spring bias.
The locking mechanism provides positive locking between the hinge pin and the hinge leaf, to ensure that once the height of the panels has been adjusted, the height adjustment is maintained (within a small variation due to pivotal movement of the hinge leaf as its associated panel is opened and closed). Furthermore, by locating the locking mechanism at the lower end of the hinge pin, it is readily accessible, even if the carriage is located in a track and the top end of the hinge pin is concealed behind a pelmet.
In another embodiment, the locking mechanism is a U-shaped clip which fits around the head of the hinge pin and engages axial slots in the hinge leaf knuckle.
In order that the invention may be more fully understood and put into practice, preferred embodiments thereof will now be described by way of example, with reference to the accompanying drawings.